Texans are young and diverse. GOP primary voters are not.

Texas state Rep. Jason Villalba (R-Dallas) authored an open letter earlier this week where he lamented that “5.5% of voters have been given 100% authority to determine what our Republican Party looks like and stands for.” The 5.5 percent he referred to is the percentage of registered voters who cast a ballot in the May 27 Republican primary.

Who participates in the Republican primary and comprises the 5.5 percent with whom Rep. Villalba is at odds on many issues? Data compiled by Labels & Lists based on voter files and other ancillary data provide us with a partial window on these influential voters who play a Texas-sized role in determining the direction of politics and public policy in the Lone Star State.

The available Labels & Lists data indicate that at the minimum an estimated 84 percent of Texans who cast a ballot in the March 2014 Republican primary were Anglo, while 6 percent were Hispanic, 1 percent African American, and 1 percent Asian American. Insufficient information existed to estimate the ethnicity/race of the remaining 8 percent, which without question includes additional African Americans and Hispanics, but also some additional Anglos as well. Today less than half (47 percent) of Texans 18 and over are Anglo, but these data reveal the considerable extent to which the Republican primary remains an Anglo-dominated affair.

These same data underscore the relatively advanced age of Texas Republican primary voters, whose median age in 2014 was 63. The median Texas adult in 2014 was 44, almost 20 years younger. In all, Texans 60 and older accounted for 59 percent of the March 4 Republican voters, while those adults under 40 represented a mere 9 percent. These proportions differ sharply from those found in the general Texas population, with Texans 60 and over comprising a mere 10 percent of the state’s population and those 18 to 39, 42 percent. If today’s youth represent the state’s future, then the future would appear to be very poorly represented in the Texas Republican primary.

One dimension upon which Republican primary voters are representative of the state population is their gender. Women and men were equally (50 percent each) represented at the ballot box on March 4, almost just as they are within the state’s adult population, where women slightly outnumber men at 51 percent.

Mark P. Jones is the Baker Institute’s fellow in political science as well as the Joseph D. Jamail Chair in Latin American Studies and the chair of the Department of Political Science at Rice University.